Hair conditioners, and hair colorants are well-known and frequently used hair care products. The major problem with current hair conditioners and non-oxidative hair dyes is that they lack the required durability for long-lasting effects. Oxidative hair dyes provide long-lasting color, but the oxidizing agents they contain cause hair damage. In order to improve the durability of these compositions, peptide-based hair conditioners, hair colorants, and other benefit agents have been developed (Huang et al., copending and commonly owned U.S. Patent Application Publication No.2005/0050656, and U.S. patent application Ser. No. 11/074,473). The peptide-based hair conditioners or colorants are prepared by coupling a specific peptide sequence that has a high binding affinity to hair with a conditioning or coloring agent, respectively. The peptide portion binds to the hair, thereby strongly attaching the conditioning or coloring agent. Peptides with a high binding affinity to hair have been identified using phage display screening techniques (Huang et al., supra; Estell et al. WO 0179479; Murray et al., U.S. Patent Application Publication No. 2002/0098524; Janssen et al., U.S. Patent Application Publication No. 2003/0152976; and Janssen et al., WO 04048399). The 0179479, 2002/0098524, 2003/0152976, and 04048399 applications describe contacting a peptide library with a hair sample in the presence of a dilute solution of bath gel (i.e., a 2% aqueous solution) and washing the phage-peptide-hair complex with the bath gel solution during phage display screening; however, the concentration of bath gel used is too low to identify bath gel-resistant hair-binding peptides. Additionally, the 04048399 application describes experiments done to determine the stability of phage peptide libraries in a 2% solution of shampoo. It was reported therein that the titer of the phage libraries incubated in the dilute shampoo solution for two hours decreased by two orders of magnitude. No shampoo resistant hair-binding peptides were described in that disclosure.
The hair-binding peptides have decreased binding affinity in the presence of a shampoo matrix and therefore do not bind strongly to hair from the shampoo matrix or are washed from the hair by the application of shampoo. Moreover, the hair-binding peptides are not stable for long periods of time in the shampoo matrix, which causes their binding affinity to decrease with time in a shampoo product.
Methods for identifying hair conditioner-resistant hair-binding peptides (Wang et al., copending and commonly owned U.S. Patent Application No. 60/657,496), skin care composition-resistant skin-binding peptides (Wang et al., copending and commonly owned U.S. Patent Application No. 60/657,494) and shampoo-resistant antibody fragments that bind to a cell surface protein of Malassezia furfur (Dolk et al., Appl. Environ. Microbiol. 71:442-450 (2005)) have been reported.
The problem to be solved, therefore, is to provide hair-binding peptides that are able to bind to hair from a shampoo matrix and are stable therein.
Applicants have solved the stated problem by discovering a method for identifying shampoo-resistant hair-binding peptides. The identified shampoo-resistant hair-binding peptide sequences bind to hair from a shampoo matrix. These hair-binding peptides may be used to prepare peptide-based hair benefit agents, such as conditioners and colorants, having improved binding affinity to hair in the presence of a shampoo and improved stability in shampoo compositions. Additionally, the shampoo-resistant peptide-based hair benefit agents may be more resistant to shampoo treatment.